[pianotech] Steinway A Bass String Rescaling

Ron Nossaman rnossaman at cox.net
Fri May 22 21:33:06 MDT 2009


William Truitt wrote:

> You ask:  Why does the inharmonicity in the low bass have to be higher than
> the lowest point of the curve? (Which is usually represented at the bass
> tenor break).  I don't know.  That is something we generally see in the
> scaling programs, and I have never seen an explaination of why that must be
> so.  Nor do I know what limits there are that would necessarily make it so.
> But since you ask the question, what kind of inharmonicity curve do you
> desire, and how much of it is achievable?  Since scaling is always a set of
> trade-offs, where do your priorities fall and in what order?  

 From what I've seen, the high inharmonicity in the low bass 
comes from the structural steel dimensioned cores. Get the 
core sizes down, and the inharmonicity goes down too. As I 
said, the near universal inclination seems to be to consider 
inharmonicity first, but other than how the curve connects at 
the transitions, I don't pay it much attention at all. My 
priorities are tension first, and Z. Then avoiding low break% 
in the low tenor and too high break% in the high bass (if I 
get to change the bridges and have a choice), with 
inharmonicity, as I said, going along for the ride. I couldn't 
tell you what the inharmonicity numbers are where, because I 
don't pay them any attention. I do know that more reasonably 
sized core wires, tensions, and break% produce a much nicer 
bass than was typically originally there. These parameters 
aren't chosen to make the inharmonicity curve go anywhere in 
particular, they are chosen to improve the partials mix and 
sound, and the lower inharmonicity is the incidental result.


> As for your concept alert, I would say this:  Smoothing and blending the
> curves of an existing scale does improve it, and makes it better at what it
> already is.  

The way it was worded, it read for me that you wanted to avoid 
improving the scale. <G>
Ron N


More information about the pianotech mailing list

This PTG archive page provided courtesy of Moy Piano Service, LLC